1. Field of the Invention
The present invention relates to an image processing device and an image processing program which display an image by superimposing a plurality of layers.
2. Description of Related Art
There is known a method of constructing and displaying a single image by superimposing a plurality of layers when displaying an image on a display provided to a computer, a smartphone, a tablet or the like. That is, each layer is an image region like a transparent film where an image is fused such that a layer superimposed below each layer is seen through a transparent image region outside an image region corresponding to an opaque object provided in each layer. The layers can be superimposed on top of one another while changing the position of each layer relative to another layer, and an image of an object rendered in each layer can be arranged at a desired position by moving each layer in a sliding motion. Moreover, an image of an object rendered by changing the opacity of a layer can be made partially transparent.
In an electronic game, for example, a single image is constructed and displayed on the display by superimposing a layer in which a background image is rendered, a character layer in which an image of a character appearing in a game is rendered, an HUD layer in which an image indicating a condition or the like of a friend or enemy character is rendered, and the like.
In order to reduce the load on a CPU at the time of such image rendering, there is disclosed a technique where a first region to be an index for a timing to input an operation is subjected to rendering at a frame rate higher than that of a second region (Japanese Patent No. 4948217, for example).